Research On Trajectory Measurement While Drilling Based On MEMS Gyroscope

The geological conditions of China’s coal mines are complex,and various disasters and accidents occur frequently during the mining process,of which gas accidents are the most costly.Whether the actual trajectory of the drill hole is consistent with the design of the drill hole directly determines the effectiveness of gas extraction and accident prevention,so it is important to measure the actual trajectory of the drill hole to evaluate the effectiveness of gas extraction.The traditional inclinometer measures the attitude when the drill rig is stopped and the drill pipe is installed to reduce the vibration disturbance caused by the drilling process,but it cannot obtain the real-time attitude information of the drilling tool.Therefore,there is an urgent need for a borehole trajectory measurement system to achieve accurate measurement and real-time display of the trajectory of gas extraction boreholes in the coal production process.In response to the above problems,this thesis designs a borehole trajectory measurement system,and the work done and the corresponding results achieved in completing the system research are as follows:(1)The basic components of the borehole trajectory measurement system and the measurement principles were studied,and the coordinate system commonly used in the trajectory navigation system was converted to a borehole coordinate system suitable for drilling operations,taking into account the characteristics of coal mine drilling operations.Based on the analysis of the measurement principle of MEMS(Micro-ElectroMechanical System)inertial sensors(tri-axial accelerometer,tri-axial gyroscope),the calculation of parameters related to the downhole borehole trajectory and the representation of the trajectory is given.(2)Analysis of the noise disturbance to the sensor during dynamic measurement and the characteristics of the sensor signal present tabu search algorithm and variational modal decomposition(TS-VMD)combined with correlation analysis algorithm and an improved limit recursive averaging algorithm for noise reduction of the sensor signal.The vulnerability of accelerometers to vibration and the use of magnetometers to interference from external magnetic fields are addressed.The superiority of the improved noise reduction algorithm is demonstrated through simulation experiments,laying the foundation for the accuracy of the subsequent trajectory measurement system.(3)According to the requirements of the borehole trajectory measurement system,the overall framework of the system was designed,and on this basis,the hardware circuit design of the dynamic inclination sensor based on STM32 and HDA436 T was completed,mainly including the STM32 main control chip and its peripheral circuit,a serial communication module,a storage module,a power supply module,and a sensor module for collecting data.It also completed the design of the underground measurement unit,transmission unit,and upper computer software of the drilling measurement system,which realized the functions of acquisition,transmission,and storage of borehole trajectory parameters as well as 3D real-time display of trajectory.Figure [71] Table [7] Reference [95]...